U.S. patent application number 14/848436 was filed with the patent office on 2016-03-17 for imprint method, imprint apparatus, and method of manufacturing article.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Kazuki Nakagawa.
Application Number | 20160077451 14/848436 |
Document ID | / |
Family ID | 55454658 |
Filed Date | 2016-03-17 |
United States Patent
Application |
20160077451 |
Kind Code |
A1 |
Nakagawa; Kazuki |
March 17, 2016 |
IMPRINT METHOD, IMPRINT APPARATUS, AND METHOD OF MANUFACTURING
ARTICLE
Abstract
The present invention provides an imprint method of molding an
imprint material supplied on a shot region of a substrate by a mold
having a pattern region in which a pattern has been formed, the
method comprising a deformation step of performing, based on
information indicating at least one among a shape of the pattern
region and a shape of the shot region, deformation of at least one
region among the pattern region and the shot region, an estimation
step of estimating a moving amount of a mark by the deformation,
the mark being provided in the at least one region, and an overlay
step of performing, based on the moving amount and detection
results of positions of a mark in the pattern region and a mark in
the shot region, overlay between the pattern region and the shot
region.
Inventors: |
Nakagawa; Kazuki;
(Utsunomiya-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
55454658 |
Appl. No.: |
14/848436 |
Filed: |
September 9, 2015 |
Current U.S.
Class: |
264/40.1 ;
425/150 |
Current CPC
Class: |
G03F 7/0002 20130101;
G03F 9/7042 20130101 |
International
Class: |
G03F 9/00 20060101
G03F009/00; G03F 7/00 20060101 G03F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 17, 2014 |
JP |
2014-189443 |
Claims
1. An imprint method of molding an imprint material supplied on a
shot region of a substrate by a mold having a pattern region in
which a pattern has been formed, the method comprising: a
deformation step of performing, based on information indicating at
least one among a shape of the pattern region and a shape of the
shot region, deformation of at least one region among the pattern
region and the shot region such that the shape of the pattern
region and the shape of the shot region get close to each other; an
estimation step of estimating a moving amount of a mark by the
deformation, the mark being provided in the at least one region
where has been deformed in the deformation step; and an overlay
step of performing, based on the moving amount and detection
results of positions of a mark in the pattern region and a mark in
the shot region, overlay between the pattern region and the shot
region in a state in which the at least one region has been
deformed in the deformation step.
2. The method according to claim 1, wherein in the overlay step,
overlay between the pattern region and the shot region is performed
based on respective positions of the mark in the pattern region and
the mark in the shot region, the respective positions being
obtained by correcting the detection results with the moving
amount.
3. The method according to claim 1, wherein the overlay step
includes a step of adjusting relative positions of the pattern
region and the shot region based on the detection results such that
the shape of the at least one region where has been deformed in the
deformation step is maintained.
4. The method according to claim 1, wherein the overlay step
includes a step of performing at least one of magnification
correction and trapezoid correction between the pattern region and
the shot region.
5. The method according to claim 1, wherein in the estimation step,
the moving amount of the mark which should be detected in the
overlay step is estimated.
6. The method according to claim 1, wherein the information is
obtained by using detection results of respective positions of
marks having a first number among a plurality of marks which are
provided in each of the pattern region and the shot region, and in
the overlay step, the overlay is performed by using detection
results of respective positions of marks having a second number
among the plurality of marks provided in each of the pattern region
and the shot region, the second number being smaller than the first
number.
7. The method according to claim 6, wherein the marks which should
be detected to obtain the information includes the marks which
should be detected in the overlay step.
8. The method according to claim 6, wherein each of the pattern
region and the shot region has a rectangular shape, and in the
overlay step, the overlay is performed by using detection results
of positions of marks respectively arranged at four corners of the
pattern region and four corners of the shot region.
9. The method according to claim 1, wherein in the overlay step,
the overlay is performed in a state in which the mold and the
imprint material contact each other.
10. The method according to claim 9, wherein in the deformation
step, the at least one region is deformed in the state in which the
mold and the imprint material contact each other.
11. An imprint apparatus that molds an imprint material supplied on
a shot region of a substrate by a mold having a pattern region in
which a pattern has been formed, the apparatus comprising: a
deformation unit configured to deform at least one region among the
pattern region and the shot region; and a control unit, wherein the
control unit causes the deformation unit to perform, based on
information indicating at least one among a shape of the pattern
region and a shape of the shot region, deformation of at least one
region among the pattern region and the shot region such that the
shape of the pattern region and the shape of the shot region get
close to each other, estimates a moving amount of a mark by the
deformation, the mark being provided in the at least one region
where has deformed by the deformation unit, and controls overlay
between the pattern region and the shot region based on the moving
amount and detection results of positions of a mark in the pattern
region and a mark in the shot region in a state in which the at
least one region has been deformed by the deformation unit.
12. A method of manufacturing an article, the method comprising
steps of: forming a pattern on a substrate using a imprint method;
and processing the substrate, on which the pattern has been formed,
to manufacture the article, wherein the imprint method is a method
of molding an imprint material supplied on a shot region of the
substrate by a mold having a pattern region in which the pattern
has been formed, and includes: a deformation step of performing,
based on information indicating at least one among a shape of the
pattern region and a shape of the shot region, deformation of at
least one region among the pattern region and the shot region such
that the shape of the pattern region and the shape of the shot
region get close to each other; an estimation step of estimating a
moving amount of a mark by the deformation, the mark being provided
in the at least one region where has been deformed in the
deformation step; and an overlay step of performing, based on the
moving amount and detection results of positions of a mark in the
pattern region and a mark in the shot region, overlay between the
pattern region and the shot region in a state in which the at least
one region has been deformed in the deformation step.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an imprint method, an
imprint apparatus, and a method of manufacturing an article.
[0003] 2. Description of the Related Art
[0004] An imprint apparatus that molds an imprint material supplied
onto a substrate by using a mold has received attention as one of
lithography apparatuses for mass-producing semiconductor devices,
magnetic storage media, and the like. The imprint apparatus is
required to accurately overlay a pattern region on the mold and a
shot region on the substrate. Japanese Patent Laid-Open No.
2013-102132 has proposed a method of accurately overlaying a
pattern region and a shot region by applying a force to a mold to
deform the pattern region in combination with heating a substrate
to deform the shot region.
[0005] In the imprint apparatus, for example, the pattern region
and the shot region are deformed based on information indicating
their shapes, and then overlay between the pattern region and the
shot region is performed based on the detection results of the
positions of a mark in the pattern region and a mark in the shot
region. In such an imprint apparatus, when the pattern region and
the shot region are deformed, the moving amount of the position of
the mark in the pattern region and the moving amount of the
position of the mark in the shot region by the deformation may be
different. In this case, it can be difficult to accurately overlay
the pattern region and the shot region if overlay is performed so
as to match the mark in the pattern region and the mark in the shot
region without considering their moving amounts.
SUMMARY OF THE INVENTION
[0006] The present invention provides a technique advantageous in,
for example, accurately overlaying a pattern region on a mold and a
shot region on a substrate.
[0007] According to one aspect of the present invention, there is
provided an imprint method of molding an imprint material supplied
on a shot region of a substrate by a mold having a pattern region
in which a pattern has been formed, the method comprising: a
deformation step of performing, based on information indicating at
least one among a shape of the pattern region and a shape of the
shot region, deformation of at least one region among the pattern
region and the shot region such that the shape of the pattern
region and the shape of the shot region get close to each other; an
estimation step of estimating a moving amount of a mark by the
deformation, the mark being provided in the at least one region
where has been deformed in the deformation step; and an overlay
step of performing, based on the moving amount and detection
results of positions of a mark in the pattern region and a mark in
the shot region, overlay between the pattern region and the shot
region in a state in which the at least one region has been
deformed in the deformation step.
[0008] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a view showing an imprint apparatus according to
the first embodiment;
[0010] FIG. 2 is a flowchart showing the flow of alignment in the
imprint apparatus according to the first embodiment;
[0011] FIG. 3A is a view showing the shape of a pattern region and
the shape of a shot region;
[0012] FIG. 3B is a view showing the shape of the pattern region
and the shape of the shot region when the shape of the pattern
region and the shape of the shot region are brought close to each
other;
[0013] FIG. 4A is a view showing a state in which a position
deviation is caused between marks at the four corners of the
pattern region and marks at the four corners of the shot region;
and
[0014] FIG. 4B is a view for explaining overlay between the pattern
region and the shot region.
DESCRIPTION OF THE EMBODIMENTS
[0015] Exemplary embodiments of the present invention will be
described below with reference to the accompanying drawings. Note
that the same reference numerals denote the same members throughout
the drawings, and a repetitive description thereof will not be
given.
First Embodiment
[0016] An imprint apparatus 1 according to the first embodiment of
the present invention will be described with reference to FIG. 1.
The imprint apparatus 1 is used to manufacture a semiconductor
device or the like. The imprint apparatus 1 performs an imprint
process of molding an imprint material 14 on a substrate by using a
mold 7 with a pattern region in which a pattern has been formed.
For example, the imprint apparatus 1 cures the imprint material 14
in a state in which the mold 7 and the imprint material 14 (resin)
on the substrate contact each other. Then, the imprint apparatus 1
widens the interval between the mold 7 and a substrate 11,
separates (releases) the mold 7 from the cured imprint material 14,
and thus can form a pattern made of the imprint material 14 on the
substrate. Methods of curing an imprint material include a heat
cycle method using heat and a photo-curing method using light. In
the first embodiment, an example in which the photo-curing method
is adopted will be described. The photo-curing method is a method
of supplying an uncured ultraviolet-curing resin as the imprint
material onto a substrate, and irradiating the imprint material
with ultraviolet rays in the state in which the mold and the resin
contact each other, thereby curing the imprint material.
[0017] [Apparatus Configuration]
[0018] FIG. 1 is a view showing the imprint apparatus 1 according
to the first embodiment. The imprint apparatus 1 can include, for
example, a mold holding unit 3 that holds the mold 7, a substrate
stage 4 that holds the substrate 11, an irradiation unit 2,
detection units 22, and a supply unit 5. The mold holding unit 3 is
fixed to a bridge plate 25 supported by a base plate 24 via a
column 26. The substrate stage 4 is configured to be movable on the
base plate 24. The imprint apparatus 1 includes a control unit 6
that includes a CPU and a memory, and controls the imprint process
(controls each unit of the imprint apparatus 1). The imprint
process is performed by executing a program stored in the memory of
the control unit 6.
[0019] The mold 7 is generally made of a material capable of
transmitting ultraviolet rays, such as quartz. A three-dimensional
pattern for molding the imprint material 14 on the substrate 11 is
formed in a partial region (pattern region 7a) on the
substrate-side surface. The substrate 11 is, for example, a
single-crystal silicon substrate or an SOI (Silicon On Insulator)
substrate. The supply unit 5 supplies the imprint material 14
(ultraviolet-curing resin) onto the upper surface (surface to be
processed) of the substrate 11.
[0020] The mold holding unit 3 includes a mold chuck 15 that holds
the mold 7 by a vacuum chuck force, an electrostatic force, or the
like, and a mold driving unit 16 that drives the mold chuck 15 in
the Z direction. The mold chuck 15 and the mold driving unit 16
have an aperture region 17 at their center portions (insides), and
are configured so that light emitted by the curing unit 2 passes
through the mold 7 to irradiate the substrate 11. The pattern
region 7a on the mold has, for example, a rectangular shape.
However, the pattern region 7a sometimes includes a deformation
component such as a magnification component or a trapezoidal
component owing to a manufacturing error, a thermal deformation, or
the like. To cancel this, the mold holding unit 3 includes a
pressure unit 18 that deforms the pattern region 7a by adding a
force to a plurality of portions on the side surface of the mold 7.
The deformation component in the pattern region 7a can be corrected
and the pattern region 7a of the mold 7 can be deformed into a
desired shape by adding the force to the plurality of portions on
the side surfaces of the mold 7 by the pressure unit 18, as
described above. The pressure unit 18 can include a plurality of
actuators such as piezoelectric actuators.
[0021] The mold driving unit 16 includes an actuator such as a
linear motor or an air cylinder, and drives the mold chuck 15 (mold
7) in the Z direction so as to bring the mold 7 into contact with
the imprint material 14 on the substrate or separate it from the
imprint material 14 on the substrate. Since high-accuracy alignment
is requested of the mold driving unit 16 when bringing the mold 7
and the imprint material 14 on the substrate into contact with each
other, the mold driving unit 16 may be constituted by a plurality
of driving systems such as a coarse driving system and a fine
driving system. The mold driving unit 16 may have, for example, a
position adjustment function of not only driving the mold 7 in the
Z direction but also adjusting the position of the mold 7 in the X
and Y directions and the .theta. direction (rotational direction
around the Z-axis), and a tilt function of correcting the tilt of
the mold 7. In the imprint apparatus 1 according to the first
embodiment, the mold driving unit 16 performs an operation of
changing the distance between the substrate 11 and the mold 7.
However, a stage driving unit 20 of the substrate stage 4 may
perform this operation, or both the stage driving unit 20 and the
mold driving unit 16 may perform this operation.
[0022] The substrate stage 4 includes a substrate holding unit 19
and the stage driving unit 20, and drives the substrate 11 in the X
and Y directions. The substrate holding unit 19 holds the substrate
11 by a holding force such as a vacuum chuck force or an
electrostatic force. The stage driving unit 20 mechanically holds
the substrate holding unit 19, and drives the substrate holding
unit 19 (substrate 11) in the X and Y directions. The stage driving
unit 20 may use, for example, a linear motor and may be constituted
by a plurality of driving systems such as a coarse driving system
and a fine driving system. The stage driving unit 20 may have, for
example, a driving function of driving the substrate 11 in the Z
direction, a position adjustment function of rotating and driving
the substrate 11 in the .theta. direction to adjust the position of
the substrate 11, and a tilt function of correcting the tilt of the
substrate 11.
[0023] A position measurement unit 40 measures the position of the
substrate stage 4. The position measurement unit 40 includes, for
example, a laser interferometer or an encoder and measures the
position of the substrate stage 4. An example in which the position
measurement unit 40 includes the laser interferometer will be
described here. The laser interferometer irradiates a reflecting
plate provided on the side surface of the substrate stage 4 (for
example, the substrate holding unit 19) with a laser beam, and
detects a displacement from a reference position on the substrate
stage 4 based on the laser beam reflected by the reflecting plate.
Based on the displacement detected by the laser interferometer, the
position measurement unit 40 can measure the current position of
the substrate stage 4.
[0024] Each detection unit 22 detects the positions of marks
(alignment marks) provided in the pattern region 7a and marks
(alignment marks) provided in a shot region 12. In order to
accurately overlay the pattern region 7a and the shot region 12, it
is desirable to detect as many marks as possible provided in the
pattern region 7a and the shot region 12, respectively. Therefore,
in order to detect many marks at the same time without decreasing
throughput in the imprint apparatus 1, many detection units 22 that
detect the marks provided in the pattern region 7a and the shot
region 12 need to be provided. However, if the imprint apparatus 1
includes many detection units 22, an apparatus configuration can be
complicated and an apparatus cost can also be increased. Therefore,
the imprint apparatus 1 includes the number (second number) of
detection units 22 that can only detect some marks out of the
plurality of marks provided in the pattern region 7a and the shot
region 12, respectively, at the same time. In the first embodiment,
for example, the imprint apparatus 1 includes the four detection
units 22 such that the marks respectively provided at the four
corners of the pattern region 7a and the four corners of the shot
region 12 can be detected at the same time.
[0025] The shot region 12 on the substrate has, for example, a
rectangular shape. However, the shot region 12 sometimes includes a
deformation component such as a magnification component or a
trapezoidal component owing to an influence of, for example, a
series of semiconductor device manufacturing steps. In this case,
in order to accurately overlay the pattern region 7a on the mold
and the shot region 12 on the substrate, the pressure unit 18 may
deform the shot region 12 as well as the pattern region 7a.
Therefore, as will be described later, the imprint apparatus 1
according to the first embodiment can include a heating unit 50
that deforms the shot region 12 by heating the substrate 11. That
is, in the first embodiment, at least one of the pressure unit 18
and the heating unit 50 can be used as a deformation unit that
deforms at least one of the pattern region 7a and the shot region
12.
[0026] The irradiation unit 2 can include a curing unit 9 that
cures the imprint material 14 on the substrate by irradiating the
imprint material 14 with light, and the heating unit 50 that
deforms the shot region 12 by irradiating the substrate 11 with
light. The irradiation unit 2 can also include an optical member 10
that guides, onto the substrate, light emitted by the curing unit 9
and light emitted by the heating unit 50. In the imprint apparatus
1 according to the first embodiment, as shown in FIG. 1, the curing
unit 9 and the heating unit 50 are formed as one unit. However, the
present invention is not limited to this, and they may be formed as
separate units. The curing unit 9 can include a light source that
emits light (ultraviolet rays) for curing the imprint material 14
on the substrate, and an optical system that shapes light emitted
by the light source into light suitable for the imprint process.
The heating unit 50 can include a light source that emits light
having a certain wavelength suitable for heating the substrate 11
without curing the imprint material 14 supplied onto the substrate,
and a light adjustment unit configured to adjust the intensity of
light emitted by the light source. The light adjustment unit of the
heating unit 50 adjusts the intensity of light irradiating the
substrate 11 so that the temperature distribution in the shot
region 12 becomes a desired one. As the light adjustment unit of
the heating unit 50, for example, a liquid crystal device or a
digital mirror device (DMD) is available.
[0027] [Imprint Process]
[0028] The imprint process in the imprint apparatus 1 according to
the first embodiment will now be described. The control unit 6
controls the substrate stage 4 so that the shot region 12 on the
substrate where the pattern of the mold 7 should be transferred is
arranged below the supply unit 5. When the shot region 12 is
arranged below the supply unit 5, the control unit 6 controls the
supply unit 5 to supply the imprint material 14 to the shot region
12. After the imprint material 14 is supplied to the shot region
12, the control unit 6 controls the substrate stage 4 so that the
shot region 12 is arranged below the pattern region 7a on the mold.
When the shot region 12 is arranged below the pattern region 7a on
the mold, the control unit 6 controls the mold driving unit 16 to
drive the mold 7 in the -Z direction, and brings the mold 7 and the
imprint material 14 on the substrate into contact with each other
(pressing step). Then, the control unit 6 waits for an elapse of a
predetermined time in the state in which the mold 7 and the imprint
material 14 on the substrate contact each other. The imprint
material 14 on the substrate can thus completely fill the pattern
of the mold 7.
[0029] The control unit 6 performs alignment between the shot
region 12 and the pattern region 7a of the mold 7 in the X and Y
directions in the state in which the mold 7 and the imprint
material 14 on the substrate contact each other. Alignment can
include a "deformation step" of deforming the pattern region and
the shot region such that the shape of the pattern region 7a and
the shape of the shot region 12 get close to each other, and an
"overlay step" of overlaying the pattern region 7a and the shot
region 12. Alignment between the pattern region 7a and the shot
region 12 will be described in detail later. After performing
alignment between the pattern region 7a and the shot region 12, the
control unit 6 controls the curing unit 9 to irradiate the imprint
material 14 on the substrate with light (ultraviolet rays) via the
mold 7. Then, the control unit 6 controls the mold driving unit 16
to drive the mold 7 in the +Z direction and separates the mold 7
from the imprint material 14 on the substrate that has been cured
by irradiation with light (separation step). This makes it possible
to mold the imprint material 14 on the substrate by using the mold
7 and form the pattern made of the imprint material 14 on the
substrate. Such an imprint process is performed for each of the
plurality of shot regions 12 on the substrate.
[0030] [Alignment]
[0031] Alignment in the imprint apparatus 1 according to the first
embodiment will now be described. In the imprint apparatus 1, for
example, at least one region among the pattern region 7a and the
shot region 12 is deformed based on information, obtained in
advance, indicating at least one of the shape of the pattern region
7a and the shape of the shot region 12. When at least one region
among the pattern region 7a and the shot region 12 is deformed
based on the information as described above, a relative position
deviation may occur between the pattern region 7a and the shot
region 12. To cope with this, in alignment in the imprint apparatus
1 according to the first embodiment, the "overlay step" is
performed, in addition to the "deformation step" of deforming at
least one region among the pattern region 7a and the shot region 12
based on the information. In the overlay step, the shapes and the
relative positions of the pattern region 7a and the shot region 12
are corrected based on a result of a detection by each detection
unit 22 in a state in which at least one region among the pattern
region 7a and the shot region 12 has been deformed in the
deformation step.
[0032] The deformation step is a step of deforming at least one
region among the pattern region 7a and the shot region 12 so as to
correct a high-order component such as an arcuate component or a
barrel component included in the pattern region 7a or the shot
region 12. Therefore, the deformation step may be performed based
on the information obtained by detecting as many marks as possible
out of the plurality of marks provided in the pattern region 7a and
the shot region 12, respectively. In the first embodiment, the
information is obtained by detecting the first number (for example,
nine) of marks out of the plurality of marks provided in the
pattern region 7a and the shot region 12, respectively.
[0033] On the other hand, the overlay step is a step of overlaying,
based on the result of the detection by each detection unit 22, the
pattern region 7a and the shot region 12 so as to correct a
low-order component such as shift correction or magnification
correction between them. The overlay step can be performed in a
state in which the pattern region 7a and the shot region 12 have
been deformed in the deformation step. That is, the overlay step
only corrects the low-order component, and thus can be performed by
using the marks smaller in number than the marks detected to obtain
the information used in the deformation step. In the first
embodiment, the four detection units 22 detect, in the overlay
step, the marks having the second number (four) smaller than the
first number arranged at the four corners of the pattern region
having the rectangular shape and at the four corners of the shot
region having the rectangular shape. As described above, only the
low-order component is corrected in the overlay step. It is
therefore possible to reduce the number of detection units 22, and
suppress complication of the apparatus configuration and a decrease
in throughput.
[0034] Alignment in the imprint apparatus 1 according to the first
embodiment will be described below with reference to FIG. 2. FIG. 2
is a flowchart showing the flow of alignment in the imprint
apparatus 1 according to the first embodiment.
[0035] In step S101, the control unit 6 obtains the information (to
be referred to as shape information hereinafter) indicating at
least one among the shape of the pattern region 7a on the mold and
the shape of the shot region 12 on the substrate. As described
above, the first number (nine) of marks out of the plurality of
marks provided in the pattern region 7a and the shot region 12 need
to be detected in order to obtain the shape information. In the
imprint apparatus 1 according to the first embodiment, however, the
number of detection units 22 is set to four (second number) smaller
than the first number in order to suppress complication of the
apparatus configuration and the decrease in throughput. Therefore,
before starting the imprint process, the first number of marks may
be detected in an external measurement apparatus of the imprint
apparatus 1, and at least one among the shape of the pattern region
7a and the shape of the shot region 12 may be obtained as the shape
information. This allows the control unit 6 to obtain the shape
information from the external measurement apparatus, and obtain the
shape difference between the pattern region 7a and the shot region
12 so as to include the high-order component.
[0036] FIG. 3A is a view showing the shape of the pattern region 7a
and the shape of the shot region 12. In FIG. 3A, a solid line 30
indicates the shape of the shot region 12 and a broken line 31
indicates the shape of the pattern region 7a. Their shapes are
respectively obtained from nine marks 30a provided in the shot
region 12 and nine marks 31a provided in the pattern region 7a. In
FIG. 3A, the shape of the shot region 12 indicated by the solid
line 30 is set to an ideal shape (rectangular shape) for the sake
of simplicity. In practice, however, a deformation including the
high-order component or the low-order component is sometimes
generated in the shot region 12 as well. That is, in FIG. 3A, it
can also be considered that, for example, the solid line 30
indicates the target shape difference between the pattern region 7a
and the shot region 12, and the broken line 31 indicates the actual
shape difference between the pattern region 7a and the shot region
12.
[0037] In the first embodiment, the shape of the pattern region 7a
and the shape of the shot region 12 as the shape information are
obtained by the external measurement apparatus of the imprint
apparatus. However, the present invention is not limited to this.
The shape of the pattern region 7a and the shape of the shot region
12 as the shape information may be obtained by repeating, for
example, detection of mark positions by the four detection units 22
and the movement of the substrate stage 4 within the imprint
apparatus 1 to detect the positions of the first number of
marks.
[0038] In step S102, the control unit 6 determines, based on the
shape information obtained in step S101, a driving amount for
driving the deformation unit (the pressure unit and the heating
unit) such that the shape of the pattern region 7a and the shape of
the shot region 12 get close to each other. That is, the control
unit 6 determines the driving amount of the deformation unit such
that the shape difference between the pattern region 7a and the
shot region 12 approaches the target shape difference. The
determined driving amount will be used in a later deformation step
(step S105). In the deformation step, in order to correct the
high-order component, it is desirable to use, in combination, the
heating unit 50 that deforms the shot region 12 by heating the
substrate 11 and the pressure unit 18 that deforms the pattern
region 7a by adding a force to the mold 7. In this case, the
control unit 6 can determine the driving amount for driving the
pressure unit 18 and the driving amount for driving the heating
unit 50 such that the shape difference between the pattern region
7a and the shot region 12 approaches the target shape difference.
If one of the pattern region 7a and the shot region 12 is deformed,
the control unit 6 can determine the driving amount for driving the
pressure unit 18 or the driving amount for driving the heating unit
50.
[0039] In step S103, the control unit 6 estimates, by deforming at
least one of the pattern region 7a and the shot region 12 in
accordance with the driving amount determined in step S102, an
amount of movement of each mark (the moving amount of each mark) in
the region where the deformation has been performed. The moving
amount may be estimated for each of the plurality of marks to be
detected in a later overlay step (step S107). FIG. 3B is a view
showing the shape of the pattern region 7a and the shape of the
shot region 12 when driving the pressure unit 18 and the heating
unit 50 in accordance with the driving amount determined in step
S102 to bring the shape of the pattern region 7a and the shape of
the shot region 12 close to each other. If the pressure unit 18
adds a force to the mold 7, unintended deformation owing to a
Poisson's ratio can be generated in the pattern region 7a. On the
other hand, if the heating unit 50 heats the substrate 11,
isotropic deformation may be generated in the shot region 12.
Therefore, the combined use of the pressure unit 18 and the heating
unit 50 makes it possible to reduce deformation of the pattern
region 7a owing to the Poisson's ratio by isotropic deformation of
the shot region 12, making it easier to bring the shape of the
pattern region 7a and the shape of the shot region 12 close to each
other. If the pressure unit 18 and the heating unit 50 are used in
combination as described above, the position deviation of the marks
may occur between, for example, the four corners of the pattern
region 7a and the four corners of the shot region 12, as shown in
FIG. 3B, when bringing the shape of the pattern region 7a and the
shape of the shot region 12 close to each other.
[0040] In this case, if the marks of the pattern region 7a and the
marks of the shot region 12 are matched in the X and Y directions
without considering the position deviation of the marks in the
later overlay step, it can be difficult to accurately overlay the
pattern region 7a and the shot region 12. Therefore, in the overlay
step, the position deviation of the marks may be considered when
overlaying the pattern region 7a and the shot region 12. That is,
in the overlay step, the moving amounts of the marks at the four
corners of the pattern region 7a and the moving amounts of the
marks at the four corners of the shot region 12 may be considered
when the pattern region 7a and the shot region 12 have been
deformed in accordance with the driving amount determined in step
S102. In the imprint apparatus 1 according to the first embodiment,
therefore, the control unit 6 obtains, based on the driving amount
determined in step S102, the moving amounts of the marks at the
four corners of the pattern region 7a and the moving amounts of the
marks at the four corners of the shot region 12. The obtained
moving amounts can be used in the later overlay step (S107).
[0041] These moving amounts can be calculated based on, for
example, information (to be referred to as deformation amount
information hereinafter) indicating the relationship between the
driving amount of the pressure unit 18 and the deformation amount
of the pattern region 7a, and the relationship between the driving
amount of the heating unit 50 and the deformation amount of the
shot region 12. The deformation amount information is represented
by, for example, a database or a function. The relationship between
the driving amount of the pressure unit 18 and the deformation
amount of the pattern region 7a can be obtained by, for example,
performing the deformation analysis of the mold 7 when driving the
pressure unit 18 in a simulation, an experiment using a dummy
substrate, or the like. Similarly, the relationship between the
driving amount of the heating unit 50 and the deformation amount of
the shot region 12 can be obtained by, for example, performing the
thermal deformation analysis of the substrate 11 when driving the
heating unit 50 in the simulation, the experiment using the dummy
substrate, or the like. Note that the dummy substrate may be a
substrate where no imprint process is performed or a substrate
where the imprint process is first performed (for example, the
first substrate in a lot) out of a plurality of substrates where
the imprint processes should be performed.
[0042] In step S104, the control unit 6 controls the mold holding
unit 3 to bring the mold 7 and the imprint material 14 supplied
onto the shot region into contact with each other. In step S105,
the control unit 6 controls the pressure unit 18 and the heating
unit 50 in accordance with the driving amount determined in step
S102 to deform the pattern region 7a and the shot region 12 such
that the shape of the pattern region 7a and the shape of the shot
region 12 get close to each other (deformation step). When the
heating unit 50 deforms the shot region 12, it takes a considerable
time for the substrate 11 to have a desired temperature
distribution. Therefore, the shot region 12 may be deformed by the
heating unit 50 during a period when the imprint material 14 and
the mold 7 are brought into contact with each other, and the
three-dimensional pattern formed on the mold 7 is filled with the
imprint material 14. Further, in step S105, both the pressure unit
18 and the heating unit 50 are controlled so as to correct the
high-order component, and both the pattern region 7a and the shot
region 12 are deformed. However, the present invention is not
limited to this. For example, at least one of the pressure unit 18
and the heating unit 50 may be controlled to deform at least one of
the pattern region 7a and the shot region 12. The deformation step
in step S105 may be performed before bringing the imprint material
and the mold into contact with each other (step S104) or may be
performed in parallel.
[0043] In step S106, the control unit 6 causes the plurality of
detection units 22 to detect the positions of the second number of
marks provided in the pattern region 7a and the shot region 12,
respectively. As described above, the imprint apparatus 1 according
to the first embodiment includes the four detection units 22 to
detect, at the same time, the positions of the marks respectively
arranged at the four corners of the pattern region 7a and the four
corners of the shot region 12. The control unit 6 causes the four
detection units 22 to detect, at the same time, the positions of
the marks arranged in the pattern region 7a and the shot region 12,
respectively.
[0044] In step S107, the control unit 6 performs overlay between
the pattern region 7a and the shot region 12 (overlay step) in the
state in which the pattern region 7a and the shot region 12 have
been deformed in the deformation step (step S105). The overlay step
can be performed based on the detection result of the position by
each detection unit 22 and the moving amount of each mark estimated
in step S103. The overlay step can be performed based on, for
example, the respective positions of the marks in the pattern
region 7a and the marks in the shot region 12 obtained by
correcting the detection result of the mark position by each
detection unit 22 with the moving amount of each mark estimated in
step S103. However, the overlay step is not limited to be performed
based on the mark positions obtained by correcting the result of
the detection by each detection unit 22. The overlay step may be
performed based on, for example, the shape difference between the
pattern region 7a and the shot region 12 obtained by correcting the
target shape difference between the pattern region 7a and the shot
region 12 with the moving amount of each mark.
[0045] In the overlay step, adjustment (for example, translation
shift correction or rotation correction) of the relative positions
of the pattern region 7a and the shot region 12, and deformation
(for example, magnification correction or trapezoid correction) of
at least one of the pattern region 7a and the shot region 12 are
performed. In "adjustment", translation shift correction or
rotation correction between the pattern region 7a and the shot
region 12 is performed such that the shape of the region where
deformation has been performed in the deformation step is
maintained in a state in which the deformation has been performed.
"Adjustment" can be performed by, for example, controlling the
stage driving unit 20 of the substrate stage 4. In "deformation",
magnification correction or trapezoid correction between the
pattern region 7a and the shot region 12 is performed by deforming
at least one of the pattern region 7a and the shot region 12.
[0046] Overlay between the pattern region 7a and the shot region 12
will now be described. FIGS. 4A and 4B are views for explaining
overlay between the pattern region 7a and the shot region 12. As
described above, when deforming the pattern region 7a and the shot
region 12 in accordance with the driving amount determined in step
S102, the position deviation may be caused between the marks at the
four corners of the pattern region 7a and the marks at the four
corners of the shot region 12. FIG. 4A is a view showing a state in
which the position deviation is caused between the marks at the
four corners of the pattern region 7a and the marks at the four
corners of the shot region 12. In FIG. 4A, the solid line 30
indicates the shape of the shot region 12 and the broken line 31
indicates the shape of the pattern region 7a. At this time, assume
that the overlay accuracy between the pattern region 7a and the
shot region 12 is at a desired accuracy.
[0047] In this state, if each detection unit 22 is caused to detect
only the positions of the marks provided at the four corners of the
pattern region 7a and the four corners of the shot region 12, the
control unit 6 can recognize the shape of the pattern region 7a as
a linearity shape indicated by a chain double-dashed line 32 of
FIG. 4A. Assume a case in which at least one region among the
pattern region 7a and the shot region 12 is deformed such that the
marks at the four corners of the pattern region 7a and the marks at
the four corners of the shot region 12 match in the X and Y
directions. In this case, as shown in FIG. 4B, the shape of the
shot region 12 (solid line 30) and the shape of the pattern region
7a (chain double-dashed line 32) recognized based on the detection
result overlap with each other. In practice, however, the shape of
the pattern region 7a (broken line 31) and the shape of the shot
region 12 (solid line 30) do not overlap with each other. As a
result, the overlay accuracy between the pattern region 7a and the
shot region 12 can be reduced. Therefore, in the overlay step,
overlay between the pattern region 7a and the shot region 12 is
performed such that the marks at the four corners of the pattern
region 7a and the marks at the four corners of the shot region 12
are respectively arranged in the positions determined in
consideration of the moving amounts estimated in step S103. The
positions determined in consideration of the moving amounts are, as
described above, the respective positions of the marks in the
pattern region 7a and the marks in the shot region 12 obtained by
correcting the detection results of the marks positions by the
respective detection units 22 with the moving amounts estimated in
step S103. This makes it possible to inhibit the overlay accuracy
between the pattern region 7a and the shot region 12 in the state
in which the pattern region 7a and the shot region 12 have been
deformed in the deformation step from decreasing by performing the
overlay step.
[0048] As described above, the imprint apparatus 1 according to the
first embodiment performs overlay between the pattern region 7a and
the shot region 12 based on the result of the detection by each
detection unit 22 after the deformation step of deforming the
pattern region 7a and the shot region 12 based on the shape
information. Then, the imprint apparatus 1 performs overlay between
the pattern region 7a and the shot region 12 in consideration of
the moving amounts of the marks in the regions (the pattern region
7a and the shot region 12) where deformation has been performed in
the deformation step. This allows the imprint apparatus 1 according
to the first embodiment to accurately overlay the pattern region 7a
on the mold and the shot region 12 on the substrate.
[0049] <Embodiment of Method of Manufacturing Article>
[0050] A method of manufacturing an article according to an
embodiment of the present invention is suitable for manufacturing
an article such as a microdevice (for example, a semiconductor
device) or an element having a microstructure. The method of
manufacturing an article according to the embodiment includes a
step of forming a pattern on a resin applied to a substrate by
using the imprint method (step of performing the imprint process on
the substrate), and a step of processing the substrate on which the
pattern has been formed (the substrate on which the imprint process
has been performed) in the preceding step. Further, this
manufacturing method includes other well-known steps (for example,
oxidization, deposition, vapor deposition, doping, planarization,
etching, resist removal, dicing, bonding, and packaging). The
method of manufacturing an article according to the embodiment is
superior to a conventional method in at least one of the
performance, quality, productivity, and production cost of the
article.
OTHER EMBODIMENTS
[0051] Embodiment(s) of the present invention can also be realized
by a computer of a system or apparatus that reads out and executes
computer executable instructions (e.g., one or more programs)
recorded on a storage medium (which may also be referred to more
fully as a `non-transitory computer-readable storage medium`) to
perform the functions of one or more of the above-described
embodiment(s) and/or that includes one or more circuits (e.g.,
application specific integrated circuit (ASIC)) for performing the
functions of one or more of the above-described embodiment(s), and
by a method performed by the computer of the system or apparatus
by, for example, reading out and executing the computer executable
instructions from the storage medium to perform the functions of
one or more of the above-described embodiment(s) and/or controlling
the one or more circuits to perform the functions of one or more of
the above-described embodiment(s). The computer may comprise one or
more processors (e.g., central processing unit (CPU), micro
processing unit (MPU)) and may include a network of separate
computers or separate processors to read out and execute the
computer executable instructions. The computer executable
instructions may be provided to the computer, for example, from a
network or the storage medium. The storage medium may include, for
example, one or more of a hard disk, a random-access memory (RAM),
a read only memory (ROM), a storage of distributed computing
systems, an optical disk (such as a compact disc (CD), digital
versatile disc (DVD), or Blu-ray Disc (BD).TM.), a flash memory
device, a memory card, and the like.
[0052] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
[0053] This application claims the benefit of Japanese Patent
Application No. 2014-189443 filed Sep. 17, 2014, which is hereby
incorporated by reference herein in its entirety.
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